Gas fired water heater



' M354@ f Z l j BY 35 July 20, 1954 H J, CARSON 2,684,054

GAS FIRED WATER HEATER Filed May 17, 1951 .9 A if f f /l o f,

t 7 INVENTIOR ATTORNEY Patented July 20, 1954 aan,

`"256845054 rGAS FRED'WATERLHEATER Hiram J ."-Carson, Umana, Nebr.

Applica-tion May 17, 1951, Serial N0. 226,797

(CIZ'Z-"l "-5 Claims. 1 The invention relates to-gas-fired water heaters ofthe storage type, and'has for its objects to provide certainfnew andv useful'improvements in water heaters of this character.

The water heater comprising the presentfinventank, and also 'provides 'forburn'ing 'gas in'very llarge volume'with high efficiency.

An important object of the present invention is to provide 'a 'gas-'fired `"water heater `"unit `of the storage type with 'a heating tube extending through the tank, whereinn provision `is madefor a combustion space withinthe saidi'heating tube, saidcombustionsp'ace being di'sposedim-mediately below a convection'type 'of heat "transf'evr'unit 'within said heating tube. Said "heatingV tube for practical andeconomical purposes'may befo'f-uriiform diameter throughout its :vertical A-extert within theinterior of 'the'water tank.

Afurtherobjectof the invention Ais to'iprovide an improved heat transfer unitfof lthe#crn'rection type, the body of which is-of lesser-cross sectional area than `that of `said 1lfieating-=tube, and which may be cylindrical V'or'fconiaL `lfsudh as a truncated cone having vanesfdisposediat an angle `to `the vertical on the-fexteiiori'itliereof, said vanes preferably being of relatively ligntand economical construction. vvFor ilexair'n-pl'e, i said lelement `may 'be preferably substantially hollow Vwith its lowerl end closed, and for-medflof 'either sheet metal or of non-metallic-heat resi'sting material, such as refractoryfmaterial. ISaidheat transfer element is also designed `for either permanent or Yadjustable mounting Aorsupport upon the gas burnerV unit. which latter -isf'ds- .posed below the central heating tube'ortheftank, or it may be supported from the floor or -any other desirable and appropriate manner within the heater, so as to--removablydispose the transfer element atthe most desirable orprescribedlocality in any way desired. y

The invention lc `)nte`r'nplate`sthe 'provision 'of a commodious lower `chamber within "the heater, said chamber being "in open communication with the lower end of thecentral-heatingtube within the 'Water tank -an'd 'providing for-'the admission -ofair as nec'essary-ffor'supporting. combustion.

-A 4further *object of fthe invention f is l' to ipx-ocoveringf 2'4 1 of finsulating material. vend-of the `outer water shell i9 may be suitably 2 vide an'f improved gas-fired water heater of high capacityand 'efficiency wherein provision is made for substantial increase inthe transfer 'of heat by/convection to the lower portion of the central Water tube'of the heater tank.

Numerous other objects and advantages of the invention will be apparent as it is better lunderstood from the following 4description which, taken in connection with the accompanying "drawings, discloses a lpreferred embodiment thereof.

IIn saiddrawings:

Fig. l is a central "Verticalsection'throughthe improved water heater, certain parts thereof beingshown in elevation.

Fig. 2 is a horizontal lsectional View on line V2-2 of Fig. 1, and -upon a slightly enlarged scale.

l Fig. 3 isa-similar vview taken'on line 3 3 of `ligffl-is an enlarged detail view taken's'ubstantially online-@Q4 of Fig. Y3,showing a manner -ofsupportingthe 'heat transfer yconvection unit on aconventional type of gas burner; said'view l'also illustrating a manner of Y supporting the 'burner Lunit within the lower portion of the heater casing.

Y'Referring.-to the drawings, the improved water `-heater comprises al1-insulated enclosing vhousing -9 including San-outer cylindrical shell or casing HJ and an inner shell'or casing Il spaced thereff'rom. vThe'out'er casingisprovided with an outer circular top/portion or plate I2 and an inner circular 'member vI3 spaced therefrom. The heaterffurther includes a bottom portion or base pl'atetr'nember Iii 'having a` peripheral flange l5 vsuitablysecured tothe outer casing It, yand havl#inglacentral' aperture i6 for the purpose of admitting air to the combustion space or chamber of the heater. g

Theffspace between `the Outer Wall 'portions l!) and l2, Iand -the inner wall portions Il and i3 r`above yHl `is'preferablyilled with a suitable heatinsulating medium l? ofany desired or approved 'material, vsuchas cor-k, asbestos, rock wool, or the like.

The =water heaterproper comprises a'tank E8 of substantially 1 annular cross-section, vincluding an outer -cylindrical shell `I9 and an inner tube 20 spaced therefrom to dei-lne therebetween a water chamber 22, 'saidtube constituting-an uptake passage for' combustion products. -Said Water .tank further yincludes-atop wall portion r'23 which is -or may fbe provided with-anouter The fbottorn secured as indicated at I9a to the base plate member Irl of the heater unit or by equivalent means. The water tank is also provided with a wall portion or member 25 constituting the bottom head of the tank. A substantially enclosed lower chamber 26 is disposed below the tank proper, which chamber may be surrounded by the extension of wall IS of the heater tank or by equivalent means. Access to said lower chamber is afforded by means of an opening 28a in the heater casing which is normally closed by a pair of hinged doors 2Gb preferably disposed at the front of the heater. A suitable drain outlet pipe for the water tank i8 is shown at 25a.

The described structural elements of the heater are preferably supported by suitable peripherally spaced legs 21a and thereby provide for ready access of air therebetween for supporting combustion in the burner chamber of the heater.

The annular space 28 between the water tank E8 and outer insulated shell of the heater constitutes a downtake passage for products of combustion which escape through the usual flue outlet 29 having a conventional hood element- 3G and discharge pipe 3| leading to the chimney or vent to the outside atmosphere.

The water to be heated in chamber 22 of the tank I8 is admitted through an inlet pipe 32 extending to near the bottom of the tank, and heated water is discharged from the tank through an outlet pipe 33 communicably connected with the top of the tank.

A conventional thermostat element 32a for automatic control of the heater in accordance with temperature conditions within chamber is located in and communicates with said chamber through suitable apertures in the heater casing and tank, as best seen in Fig. 2.

A gas burner element is indicated at 34 and is mounted in the upper portion of the lower heater chamber 23. For this purpose said burner may include a pair of depending recessed lug elements 35 adapted to rest upon a transverse rod or support bar 36 secured at its opposite ends to the depending wall i9 of the water tank i or by equivalent means. As illustrated said gas burner is provided with a pair of circular burner ports 3l arranged in concentric spaced relation and communicably connected to a gas and air inlet mixing tube 38. The gas supply pipe for the burner is shown at 39. The flared outer end of the mixing tube 38 may project through a pair of complementary semi-circular apertures 39a in the hinged doors 2Gb or be equivalently located. Said apertures permit opening and closing of said doors so said doors may be opened when desired to obtain access to the interior of the heater.

The combustion space or chamber of the heater is indicated at 21 and is located substantially within the lower portion of the central heating tube immediately above the top of the gas burner 34, as is best seen in Figs. l and 4. By disposing the combustion space in this locality some of the heat resulting from products of combustion from the burner, is directly communicated through the tube wall into the lower portion of the annular water tank chamber 22.

The heat transfer convection element is indicated at 4B and is preferably supported by a spindle il resting on a transverse element lia of the gas burner element 34. To this end said spindle 4I may be threaded and loosely projecting at its upper end through a central aperture 42 in the lower preferably conical wall 43 of the body of the heat transfer element which may be a substantially cylindrical or conical and hollow body member designated at 44 which preferably nests closely within the heating tube so as to be vertically adjustable therein and readily insertable thereinto. The lower end of the spindle lil is adapted to be freely supported by the transverse rod or brace element Ma extending transversely across the central air inlet aperture 34a of the burner 34 (Fig. el). The spindle 4l may be designed to support the element 40 in a permarient location or a nut 45 may threadedly engage the spindle 4| and through the medium of an intervening washer element, serve to support the body 44 of the heat transfer element 40 in vertically adjusted position within the lower end of the heating tube 2D. ln this manner the volume of the combustion space 21 in ie lower portion of the heating tube 20, and disposed between the heat transfer element and the gas burner 34, may be varied as desired in accordance with operating conditions to obtain the desired heat output from the burner to be imparted to the water through the heating tube 28.

rIhe heat transfer or convection element 4U may be of light weight and capable of economical manufacture. To this end the body of the element which may be hollow and cylindrical or conical, may be constructed of sheet metal as illustrated, or other heat resisting or refractory material.

To provide the necessary swirling movement of the hot gases of combination from the burner, the body of the heat transfer element fz is provided with a series of exteriorly disposed helical flutes, ns or vanes 46, which may be integrally formed therewith, and which flutes extend outwardly from the transfer element to terminate in closely spaced relation to the inner wall surface of the vertical heating tube 20. lf desired the heat transfer element may be constructed of other non-metallic heat resistant materials, or appropriate refractory substances. Conceivably the element may be cast as a unit of Pyrex or other glass material which may permit of economic advantages.

The described construction and location of the heat transfer element within the water heater serves to provide an adequate variable and full combustion space 2l above the burner and below the heat transfer element 43, said space and element being substantially entirely contained within the heating tube 20. It is in this described locality that a substantial amount of heat is imparted to the water for providing relatively uniform temperatures throughout the tank.

The hot products of combustion from the burner are swirled exteriorly around the heat transfer element in into intimate contact with the wall of heating tube 20 and thereafter these gases continue rising and escape through the upper end of the uptake passage or heating tube 20 at the top of the tank. Thence the heated products of combustion pass radially outwardly through the horizontal space or passage over the top of the water tank and thereafter travel downwardly through the substantially restricted annular space or downtake passage 28 between the tank i8 and the inner wall Il of the outer insulated housing 9. These hot products of combustion in their downward passage serve to further .heat the water in the tank to substantial uniform '"-temperature until the spent -`products are VVVnally discharged through `the 'aforesaid ilue'outlet'Z'S.

`.From the fforegoingit willbeobservedithe -water in the tank l 3 is heated with -very lhigh eicency and to -relatively uniform temperature. This is due inpart tothe spiral utes or vanes 46 extending transversely of the *heat transfer element il@ which serve to ltransfer 4asubstantialpart of the heat inthe initiallyheated products of combustion from 'the vburner to 'the inner tanl: wall in the tube 23. Thereafter these heatedicombustion products travel upwardlyI and thereafter pass over the top of the tank and thence downwardly through the annulardowntake passage v2-8 to further heat the water quickly and 4with great Vdis- ;patchypriorto nal `escape of said combustion products through the 'ilue outlet 2S in the casing v9.

lThe provision of the insulating material 2d overthe top of the'water tank i3 is optional'and is primarily designed to prevent too rapid heating `olthe water in the upper portion ofthe tank as compared to that in the lower portions oi the tank. The inst'antdescribed manner of providing a `combustion space within the tube 2t, coupled with the variable or adjustable `spacing of the lheat transfer element it materially labove the burner 3d, has been found to virtually render unnecessary the provision of such top tank insulation.

For the purposes of the invention it is not necessary that the heat transfer or convection element l@ be mounted on the burner illustrated and described. For example, said element may be removably secured in any desired manner within the heating tube 29.

Alternatively the heat transfer element may be directly supported from the floor or other surface exteriorly of the heater, by means of the spindle or rod il extending vertically -through the central air inlet port 34o of the gas burner vits and also downwardly through the lower heater chain- `ber 2t.

in assembling the apparatus the heat transfer element te including its loosely supporting spindie ii is first projected into the heating tube 2d u through the door aperture 26a. The burner element .34 `is next inserted into the chamber 26 so as to rest upon .the transverse rod 3E in .'t'h'eiinanner hereinbefore described. The outer doors 26h may then be closed to substantially enclose the i burner unit in its inserted position as best illustrated in Fig. fl.

For the purpose of vertically adjusting the heat transfer element lil relative to the heating tube and burner to vary the vertical extent of the combustion space 2l, the nut i5 may be threaded on spindle il so as to support the transfer element in any desired vertical position within the heating tube 2G. This adjustment may be performed prior to inserting the transfer element within the heater, or by first lowering the burner so that access to said nut 45 may be obtained through the door opening 26a.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing any of its material advantages, the form hereinbefore described being merely a preferred embodiment thereof.

What I claim is:

l. A gas fired water heater, comprising a water storage tank having a vertical open ended tube lext'ending therethrough to provide an uptake passage for combustion products, a heat transfer 'element mounted in tl'e lower 'portion of Asaid tube and including a'central body of less lcrosssectional area than that or" said tubeiand 'having elementand the lower tube end, said body having angularlyldispcsed vanes on the exterior thereof extending in close proximityto the tube wall to conduct-said combustion lproducts thereagainst and thence through said uptake passage, and a gas burner disposed substantially centrally of the 'bottom of said 4tube to re directly upwardly into lsaid combustion space, the naine emitting -area oi' said burner not exceeding the cross-sectional `dimensions of said tube.

2. A gas iired water heater, vcomprising awater storage tank having a vertical open ended tube extending therethrough to provide an uptake passage for combustion products, a heat transfer Velement mounted in the lower portion of said tube and including a central cylindrical body of Aless cross-sectional area than that of said tube and having a closed wail to prevent passage of combustion products through said body, said heat transfer element including said closed wall vdeiirning the upper end of a combustion space extending transversely of said tube between said element and the lower tube end, a plurality of 'helically disposed vanes on the exterior of said cylindrical body extending in close proximity to the tube wall to conduct said combustion products thereagainst and -thence vertically through said uptake passage, and a gas burner disposed substantially centrally or and beneath the bottom of said tube to nre directly upwardly into said combustion space and providing for ready access of secondary air to support the combustion of the burner naine, the iiame eniiting `area of said burner not exceeding the cross-sectional 'dimensions of said tube.

3. A gas iired water heater, comprising a water Astorage tank having a vertical open ended tube 'extending therethrough to provide an uptake passage for combustion products, means enclosing said tank in spaced relation thereto to provide an annular downtale passage therebetween communicating at its upper end with said uptake passage and communicating at its lower portion with a ue outlet, a heat transfer element mounted in the lower portion of said tube and including a central body of less cross-sectional area than that of said tube and having a closed wall tovprevent passage of combustion products through said body, said heat transfer element including said closed body wall defining the upper end of a combustion space extending transversely of said tube between said element and the lower tube end, said body having angularly disposed vanes on the exterior thereof extending in close proximity to the tube wall to conduct said combustion products thereagainst and thence through said uptake passage, and a gas burner disposed substantially centrally of the bottom of said tube to fire directly upwardly into said combustion space, the name emitting area of said burner not exceeding the crosssectional dimensions of said tube, whereby combustion products in said space are directed upwardly between the vanes of said heat transfer element and the tube wall to effectively heat the water in the lower tank portion, said combustion products thereafter passing upwardly through said tube and over the top of the tank and thence downwardly through said annular downtake passage surrounding the tank to said flue outlet, thereby most eiiciently utilizing the heat in said combustion products to uniformly and rapidly heat the water in the tank.

4. A gas fired water heater, comprising a water storage tank having a Vertical open ended tube extending therethrough to provide an uptake passage for combustion products, means enclosing said tank in spaced relation thereto to provide an annular downtake passage therebetween communicating at its upper end with said uptake passage and communicating at its lower portion with a iiue outlet, a heat transfer element mounted in the lower portion of said tube and including a central hollow cylindrical body of less diameter than said tube, said body having a closed bottom to prevent upward passage of combustion products through said body and having helically disposed vanes on the exterior thereof extending in close proximity to the tube wall to conduct said combustion products thereagainst and thence vertically through said uptake passage, said heat transfer element including said closed bottom defining the upper end of a combustion space extending transversely of said tube between said element and the lower tube end, and a gas burner disposed centrally of the bottom of said tube to iire directly upwardly into said combustion space, the name emitting area of said burner not exceeding the cross-sectional dimensions of said tube, said burner being spaced from the bottom of the tube for ready access of secondary air to support combustion of the burner flame, whereby the combustion products in said space are directed upwardly between the vanes of said heat transfer element and the tube wall to effectively heat the water in the lower tank portion, said combustion products thereafter passing upwardly through said tube uptake passage and over the top of the tank and thence downwardly through said annular surrounding downtake passage to said flue outlet, thereby most efficiently utilizing the heat of said combustion products to uniformly and rapidly heat the Water in the tank.

5. A gas fired water heater, comprising a water storage tank having a vertical open ended tube extending therethrough to provide an uptake passage for combustion products, a heat transfer element mounted for vertical movement in the lower portion of said tube and including a central cylindrical body of less diameter than said tube and having a closed bottom wall to prevent passage of combustion products therethrough, said heat transfer element including said closed wall defining the upper end of a combustion space extending transversely of said tube between said element and the lower tube end, said body having helically disposed vanes on the exterior thereof extending in close proximity to the tube wall to conduct said combustion products thereagainst and thence vertically through said uptake passage, a gas burner disposed substantially centrally of the bottom of said tube to fire directly upwardly into said combustion space, the flame emitting area of said burner not exceeding the cross-sectional dimensions of said tube, said burner being spaced beneath the bottom of the tube wall for ready access of secondary air to support combustion of the burner flame, and means foradjusting the height of said heat transfer element relative to said burner for varying the volume of said combustion space within said tube.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 538,589 Kemble Apr. 30, 1895 544,152 Benjumes Aug. 6, 1895 1,640,284 Mitchell Aug. 23, 1927 1,640,317 Haas et al Aug. 23, 1927 1,642,539 Choinski Sept. 13, 1927 1,745,204 Bowen Jan. 28, 1930 1,816,419 Carson July 28, 1931 2,142,409 Pontremoli Jan. 3, 1939 2,479,042 Gaines Aug. 16, 1949 2,563,817 Carson Aug. 14, 1951 FOREIGN PATENTS Number Country Date 33,773 Switzerland June 19, 1905 420,012 Great Britain Nov. 23, 1934 

